What Mendix version are you using? If I save your example texts to an xsd and wsdl file, and fix the namespaces, I can import the wsdl into mendix 5.2.0 and 4.7.2 just fine. I get a webservice with a single operation "opvragen_woonplaatsen".
Fixing the namespaces should not be necessary in your originals, if they are valid WSDL/XSD/XML. I just did that to handle your anonimisation of the URLs. If you are using Mendix 5.2.0, and cannot import the originals, I would suggest filing a support ticket with the original files if you don't want to post them here online.
I use the 5.2.0 build 1371.
The XML and WSDL are valid XML-documents, but I still get no operation in the popup 'Consumed Web Service ....' after importing the wsdl by url.
I tested with three webservices of different sources, and I got three different results...
the webservice of this question: I get no operation in the popup mentioned.
a webservice of w3schools (http://www.w3schools.com/webservices/tempconvert.asmx) which is doing all the things I expect it to do within the modeler (also on runtime).
a webservice of webservices.nl, of which I get the operations, though I'm not yet succesfull in running it
I think I follow your suggestion, in filling a support ticket.
Thank you anyway!